n. The pinna of the external ear; that part of the organ of hearing which projects from the side of the head. See pinna, and cut under ear. Also auricula.n. A chamber or one of the chambers of the heart into which the blood comes from the veins, and from which it passes into the ventricle or one of the ventricles.n. Something, or some part of a thing, like or likened to an ear: variously applied, chiefly in botany, zoölogy, and comparative anatomy.n. An instrument applied to the ears to assist in hearing; a kind of ear-trumpet.n.